# frozen_string_literal: true

module Groundskeeper
  # The `version.rb` file in an application.
  class RailsVersion
    APPLICATION_CONFIG_FILE = "%sconfig/application.rb"
    MODULE_NAME_EXPRESSION = /module (\w+)/
    VERSION_FILE = "%slib/%s/version.rb"
    VERSION_EXPRESSION = /(?<=VERSION = ")([^"]+)(?=")/

    attr_reader :relative_path, :module_file, :version_file

    def initialize(relative_path = "")
      @relative_path = relative_path
      find_version_file
    end

    def current_version
      version_file.match(VERSION_EXPRESSION) || ""
    end

    def update_version!(value)
      version_file.gsub_file VERSION_EXPRESSION, value
    end

    def exists?
      version_file.exists?
    end

    private

    def find_module_file
      @module_file = Groundskeeper::Document.new(module_file_path)
    end

    def find_version_file
      find_module_file
      @version_file = Groundskeeper::Document.new(version_file_path)
    end

    def module_file_path
      format APPLICATION_CONFIG_FILE, relative_path
    end

    def version_file_path
      format VERSION_FILE, relative_path, project_namespace
    end

    def project_namespace
      underscore(module_file.match(MODULE_NAME_EXPRESSION))
    end

    def underscore(word)
      return "" unless word.respond_to?(:gsub)

      word
        .gsub(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2')
        .gsub(/([a-z\d])([A-Z])/, '\1_\2')
        .downcase
    end
  end
end